﻿// ZipNameTransform.cs
//
// Copyright 2005 John Reilly
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
// 
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent
// modules, and to copy and distribute the resulting executable under
// terms of your choice, provided that you also meet, for each linked
// independent module, the terms and conditions of the license of that
// module.  An independent module is a module which is not derived from
// or based on this library.  If you modify this library, you may extend
// this exception to your version of the library, but you are not
// obligated to do so.  If you do not wish to do so, delete this
// exception statement from your version.


using System;
using System.IO;

using ICSharpCode.SharpZipLib.Core;

namespace ICSharpCode.SharpZipLib.Zip
{
    /// <summary>
    /// ZipNameTransform transforms name as per the Zip file convention.
    /// </summary>
    public class ZipNameTransform : INameTransform
    {
        /// <summary>
        /// Initialize a new instance of <see cref="ZipNameTransform"></see>
        /// </summary>
        /// <remarks>Relative paths default to true with this constructor.</remarks>
        public ZipNameTransform()
        {
            relativePath = true;
        }

        /// <summary>
        /// Initialize a new instance of <see cref="ZipNameTransform"></see>
        /// </summary>
        /// <param name="useRelativePaths">If true relative paths are created, 
        /// if false absolute paths are created. </param>
        public ZipNameTransform(bool useRelativePaths)
        {
            relativePath = useRelativePaths;
        }

        /// <summary>
        /// Initialize a new instance of <see cref="ZipNameTransform"></see>
        /// </summary>
        /// <param name="useRelativePaths">If true relative paths are created, 
        /// if false absolute paths are created. </param>
        /// <param name="trimPrefix">The string to trim from front of paths if found.</param>
        public ZipNameTransform(bool useRelativePaths, string trimPrefix)
        {
            this.trimPrefix = trimPrefix;
            relativePath = useRelativePaths;
        }

        /// <summary>
        /// Transform a directory name according to the Zip file naming conventions.
        /// </summary>
        /// <param name="name">The directory name to transform.</param>
        /// <returns>The transformed name.</returns>
        public string TransformDirectory(string name)
        {
            name = TransformFile(name);
            if (name.Length > 0)
            {
                if (!name.EndsWith("/"))
                {
                    name += "/";
                }
            }
            else
            {
                name = "/";
            }
            return name;
        }

        /// <summary>
        /// Transform a file name according to the Zip file naming conventions.
        /// </summary>
        /// <param name="name">The file name to transform.</param>
        /// <returns>The transformed name.</returns>
        public string TransformFile(string name)
        {
            if (name != null)
            {
                if (trimPrefix != null && name.IndexOf(trimPrefix) == 0)
                {
                    name = name.Substring(trimPrefix.Length);
                }

                if (Path.IsPathRooted(name) == true)
                {
                    // NOTE:
                    // for UNC names...  \\machine\share\zoom\beet.txt gives \zoom\beet.txt
                    name = name.Substring(Path.GetPathRoot(name).Length);
                }

                if (relativePath == true)
                {
                    if (name.Length > 0 && (name[0] == Path.AltDirectorySeparatorChar || name[0] == Path.DirectorySeparatorChar))
                    {
                        name = name.Remove(0, 1);
                    }
                }
                else
                {
                    if (name.Length > 0 && name[0] != Path.AltDirectorySeparatorChar && name[0] != Path.DirectorySeparatorChar)
                    {
                        name = name.Insert(0, "/");
                    }
                }
                name = name.Replace(@"\", "/");
            }
            else
            {
                name = "";
            }
            return name;
        }

        string trimPrefix;

        /// <summary>
        /// Get/set the path prefix to be trimmed from paths if present.
        /// </summary>
        public string TrimPrefix
        {
            get { return trimPrefix; }
            set { trimPrefix = value; }
        }

        bool relativePath;
    }
}